Liquid dispensers are widely used in various industries. Chemical solutions including fertilizers, pesticides, and detergents and so on are often mixed from various concentrates and solvents before dispensed for use or storage. Similar dispensers also find applications in the medical field. In the food and beverage industry, liquid dispensers are widely used in all kinds of venues such as quick service restaurants.
The liquid dispensers used in food and beverage industry reconstitute juice syrup concentrates with a potable diluent, e.g., potable water, and then dispense the reconstituted juice into a container at the point of consumption. This kind of dispensers are sometimes called “postmix” dispensers as they produce a final product in contrast to a “premix” beverage that is prepackaged with the final constituents (flavor, gas, etc.) and ready for consumption. For safety and taste reasons, a postmix beverage dispenser often requires refrigeration in the dispenser of various components that eventually go into the postmix product.
Past attempts at achieving a desired mix ratio between the concentrate and the diluent have left room for improvement. Many of the existing mechanisms are complicated and prone to malfunction. For example, reciprocating pistons have been used to control both the concentrate input and the diluent input. This kind of dispensers has difficulty in achieving a high flow rate and the chambers separating the two supply fluids have leak problems. Other existing mechanisms are not capable of adjusting the fluid flow when the desire ratio changes. Accordingly, there is a need for an improved yet simple mechanism to control the proper mixing ratio without compromising the flow rate itself.